Question

If a vertex of a triangle be (1, 1) and the middle points of the sides through it be (—2, 3) and (5, 2), find the other vertices.

Answer 1

the other vertex are (-4, 5) and (10, 4).
as (-2, 3) is the midpoint so you have to increase the same double

Answer 2

other vertices are
(-4,5) and (10,4)